aaa authorization commands

Syntax

aaa authorization commands <CONNECTION-TYPE> {none | group <GROUP-LIST>}

no aaa authorization commands <CONNECTION-TYPE>

Description

Defines authorization as being local RBAC (with the name none) (the default). Or defines a sequence of remote AAA servers to be accessed for authorization purposes. Each available connection type (channel) can be configured individually as either local (by specifying none) or using remote AAA server groups. All server groups named in your command, must exist. This command can be issued multiple times, once for each connection type. Local (specified as none) is always available for any connection type not configured for remote AAA authorization.

The no form of this command removes for the specified connection type, any defined remote AAA server group authorization sequence. Local RBAC authorization is available for connection types without a configured remote AAA server group list (whether default or for the specific connection type).

NOTE: Although only TACACS+ servers are supported for remote authorization, local RBAC authorization can be used with remote RADIUS authentication.

Command context

config

Parameters

<CONNECTION-TYPE>

One of these connection types (channels):

default
Defines a list of authorization server groups to be used for the default connection type. This configuration applies to all other connection types (console, ssh) that are not explicitly configured with this command. For example, if you do not use aaa authorization commands console... to define the console authorization list, then this default configuration is used for console.
console

Defines a list of authorization server groups to be used for the console connection type.

ssh

Defines a list of authorization server groups to be used for the ssh connection type.

none

Selects local RBAC authorization.

group <GROUP-LIST>

Specifies the list of remote AAA server group names. Predefined remote AAA group name tacacs is available. User-defined TACACS+ server group names may also be used. The remote AAA server groups are accessed in the order that the group names are listed in this command. Within each group, the servers are accessed in the order in which the servers were added to the group. Server groups are defined using command aaa server group and servers are added to a server group with the command server.

It is recommended to always include the special name none as the last name in the group list. If none is omitted, and no remote AAA server is reachable, authorization will not be possible.

Authority

Administrators

Usage

TACACS+ server authorization considerations
NOTE:

Use caution when configuring authorization, as it has no fail through. If the switch is not configured properly, the switch might get into an unusable state in which all command execution is prohibited.

To prevent authorization difficulties:

  • Make sure that all listed TACACS+ servers can authorize users for command execution.

  • Make sure that credential database changes are promptly synchronized across all TACACS+ servers.

  • Make sure none is included as the last name in the group list. If none is omitted, and no remote AAA server is reachable, authorization will not be possible.

  • Although not recommended, if you choose to omit none from the list, and are manipulating configuration files, special caution is necessary. If the source configuration includes TACACS+ authorization and you are copying configuration from an existing switch into the running configuration of a new switch, and you have not yet configured the interface or routing information to reach the AAA server, the switch will enter an unusable state, requiring hard reboot.

    To avoid getting into this situation that can occur when none has been omitted, do either of the following:

    • In the configuration source, delete or comment-out the line configuring remote authorization. Then, after the configuration copy and paste, manually configure authorization.

    • Move the line configuring the authorization to the end of the source configuration before copying and pasting.

Examples

Defining the default authorization sequence based on a user-defined TACACS+ server group, then the default TACACS+ server group, and finally (as a precaution), local RBAC authorization: 

switch(config)# aaa authorization commands default group tg1 tacacs none
All commands will fail if none of the servers in the group list are reachable.
Continue (y/n)? y
switch(config)#

Defining the console authorization sequence based on two user-defined TACACS+ server groups, then the default TACACS+ server group, and finally (as a precaution), local RBAC authorization: 

switch(config)# aaa authorization commands console group tg1 tg2 tacacs none
All commands will fail if none of the servers in the group list are reachable.
Continue (y/n)? y
switch(config)#

Setting the authorization for default to local RBAC. 

switch(config)# aaa authorization commands default none
switch(config)#